Fuel-controlling device

ABSTRACT

An air valve is disposed in the air flowing through a carburetor to the intake manifold of an internal combustion engine. A fuel valve controls the fuel flow to a mixing chamber which produces a suspension of fuel particles which are entrained in the airflow. The air valve is operably connected to the fuel valve through the mixing chamber.

United States Patent [72] Inventor Klrrillos ILElgohnry 1,376,707 /1921Leahy et a1. 261/44 Pittsburglnla. 1,440,940 1/1923 Smith etal...26l/D1G. 18 [21] Appl. No. 750,175 1,573,065 2/1926 Hess 261/44 [22]Filed Aug-5,1968 1,595,315 8/1926 Rayfieldm 261/44 [45] Patented July13,1971 1,789,564 1/1931 Rayfield 261/D1G. 18 [73] Assignee EnergyTransmission Corp. 1,792,495 2/1931 Heath 261/50(.1) 1,927,090 9/1933Hess 261/44 2,614,581 10/1952 Russell 261/50(.l)X [54] FUEICONTROLUNGDEVICE 2,635,625 4/1953 Moseley et a1 261/D1G. 50 CI in 70 I F 2,757,9148/1956 Ball 261/D1G. 50 3,127,453 3/1964 Sarto 26l/36(.1) [52] [1.8. CI261/36, 3,275,307 9/1966 Robechaud 261/36(.1) I. cl ggzffggg PrimaryExaminer-Tim R. Miles n. 0' sun]! 0 14:23:33; Nelson 13. Kimmelman andMaleson, Kimmelman 50.1, 36.1, D16. 18, DIG. 50

[56] Rdenncacmd ABSTRACT: An air valve is disposed in the air flowingUNITED STATES PATENTS through a carburetor to the intake manifold of aninternal 1,145,172 6/1915 Speed 261/D1G. 18 combustion engine. A fuelvalve controls the fuel flow to :1 1,234,227 7/1917 Schmid et a1. 261/44X mixing chamber which produces a suspension of fuel particles 1,293,3482/1919 Costa 261/50 (.1) which are entrained in the airflow. The airvalve is operably 1,361,529 12/1920 Marr 261/50 (.1 connected to thefuel valve through the mixing chamber.

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0. 62b 6.. 5;\ s 5 47 w PATENTED JUL 1 319m SHEU 1 BF PATENTEDJULISIQTI3,592 449 sum 3 or 4 ,4 TmzA/E 5 FUEL-CONTROLLING DEVICE BACKGROUND OFTHE INVENTION l. Field of the Invention This invention pertains to thefield of carburetors for an innal combustion engine in which the airflowinto the intake nifold is used to control the flow of fuel to a mixingamber. 2. Prior Art t is well known that an internal combustion engineprovides ximum power output when the airflow into the intake nifold isat maximum and there is a correct proportion of l to air. At any runningcondition of the engine the ultimate ver is decreased if the airflow isless than that demanded by engine. Iarburetors have been used whichinclude air valves for sing the airflow and controlling a fuel valve formetering amount of gas flow into the fuel-air mixing chamber. In theting chamber air is mixed with fuel to provide a suspension I'uelparticles which are entrained into the airflow and then a the intakemanifold of the engine. In such prior carbures the air valve has beenmechanically connected to the fuel tering valve by rigid rods which werejournaled in apertures med in the carburetor housing. When the power orsped of engine changed, these rods moved within the journal and re hasdeveloped frictional impairment of free axial movent of the rods therebyhampering the correct free response the gas valve to airflow. On theother hand if the journals re enlarged to minimize friction, fuel in theform of vapor l fuel particles would escape through the enlargedjournals m the float chamber to the mixing chamber. This escaping Iwould bypass the fuel-metering pin and seat which con- Is the air-fuelratio thereby varying the ratio from a desired ue. mother problem withprior carburetors has been in providproper damping of the air valve.Without damping, upon .nge in engine demand for air the air valve wouldbounce or illate above and below the stable or balance position for astantial period of time which resulted in inefficient opera- I. It hasbeen known to use a damper plate immersed within fuel as the dampingmedium in order to quickly damp out h oscillation. However, if thedamping factor is too high, long a period of time may be required beforethe balance ition is reached. This will increase the lag of time between:ping on or off the accelerator and the response by the ena to increaseor decrease power. Such time lag has an adse effect on the performanceof the automobile and in the :ty of the operation. Accordingly, priorcarburetors have a lot to be desired in providing an optimum dampingfacwhere the stable position is reached in as short a period of e aspossible.

BRIEF OF SUMMARY OF THE INVENTION 1 accordance with the invention thereis provided a carbur for an internal combustion engine having a housingwith air intake opening and an output opening. Air flows from intakeopening to the output opening. Fuel and air are ed in a mixing chamberwhich produces a suspension of ticles of fuel in air which are entrainedin the airflow. A l valve communicates with a fuel source and isoperable to trol the flow of fuel to the mixing chamber. An air valve isiosed in the airflow and is movable in accordance with the low from theintake to the output opening. The air valve is rably connected to thefuel valve through a coupling which ses through the mixing chamber. Inthis manner there is ided the undesirable friction forces of connectorsjour- :d in the carburetor housing.

urther in accordance with the invention the carburetor inies a dampermember disposed within a damper housing. a damper member is operablycoupled to the fuel valve. 1] flow between the damper housing and thesource of fuel electively varied to provide a variable damping factor.In

manner an optimum damping factor may be achieved.

BRIEF DESCRIPTION OF THE DRA. 'IN GS FIG. I is a sectional view of acarburetor of the present inventive concept taken along the section line1-1 of FIG. 2.

FIG. 2 is a sectional view of the carburetor of FIG. I taken along thesection line 2-2 of FIG. I.

FIG. 3 is a sectional view ofthe portion of the carburetor of FIG. Itaken along section line 3-3 of FIG. I.

FIG. 3A is a modification of the invention of FIG. I in which a swirlaction is produced.

FIGS. 4 and 5 is an exploded perspective view of the air valve, fuelmetering and damping system of FIG. 1.

FIG. 6 is a further modification of FIG. I in which a floatless chamberis used.

DETAILED DESCRIPTION OF THE DRAWINGS FIGS. 1-3 show a hollow carburetorhousing indicated generally by numeral 10 having an air intake opening11 and a second mixing chamber 12 which is in communication with aconventional intake manifold (not shown) of an internal com bustionengine.

As the engine operates it will produce suction at chamber 12 andtherefore air flows into the air intake 11 past a conven tional chokevalve [4 through chamber 12 and into the intake manifold. An air valveI5 is disposed in the airflow within chamber I2 and as the enginedemands more air the air valve senses the weight rate of airflow andmoves upwardly. A portion of the airflow passes through the inneropening of valve 15 and the remainder passes between valve I5 and theinner wall of chamber 12.

VALVE I5ROD 30--PIN 34 In the static rest position the annular body 16of air valve I5 is supported by a valve seat 17 which is adjustablysecured by a lock screw to a hollow stem 20 having an enlargedringshaped bottom portion 204. The bottom portion 200 is engaged in anannular shoulder 2| of housing 10 formed at the upper edge of chamber 22containing fuel.

Air valve IS includes a spider defined by four straight verti cal ribs15a-d extending inwardly from body [6 with the ribs meeting to form ahollow cylinder 1Se. Secured within cylinder 15: is a sleeve 24 having awasher-shaped upper member 240 and a lower portion which may be peenedunder cylinder 15c. Upper member 240 has four openings in which thereare secured respectively the lower ends of rods 25a-d. The upper ends ofrods 25a-d are secured within openings 28a-d. The upper ends of rods2Sa-d are secured within openings 28a-d respectively of a pin holder 28.Rods 25a-d may be secured to the respective openings of member 240 andholder 28 by welding, as for example. A center opening 28c of pin holder28 threadedly engages the upper end of a pin rod 30 which extendsthrough without touching a tube 32 and the inner chambers of hollow stem20. Rod 30 at its lower end, is secured in an opening in an upper endofa fuel valve metering pin 34, the lower end of which is connected to adamper plate 36. Accordingly, metering pin 34 and damper plate 36 moveupwardly and downwardly as air valve I5 is urged upwardly and downwardlyrespectively by the airflow through chamber 12.

Metering pin 34 is tapered so that as it travels in an upward directionthe annular clearing between pin 34 and a valve seat 37 threadedlyengaged within hollow stem 20, increases in area. In this manner agreater amount of fuel within chamber 22 is allowed to flow into a firstmixing chamber 39 formed within stem 20 adjacent to the upper endthereof.

The supply of air for mixing chamber 39 is taken from below valve seat17 by way of air passages 40. Tube 32 extends upwardly from chamber 39into chamber 12. In order to provide suction in chamber 3!, a pressuredifference is produced between the upper and lower sides of air valve I5which is effective to suck up the mixture of a suspension of fuelparticles in the air through tube 32. Accordingly, the mixture isdirected out of the upper and of the tube and into the air which flowsthrough second mixing chamber 12 outside of tube 32.

It will now be understood that the only mechanical coupling between airvalve 15 and metering pin 34 includes a support ing structure of rods adand holder 28 and an elongated member or rod 30, Rod 30 extendsdownwardly through tube 32 and through hollow stem 20 which includesfirst mixing chamber 39. Accordingly, there is avoided the use offriction producing members which have in the prior art heenjournaled inapertures in the carburetor housing for coupling the air valve with themetering pin and the damper plate. Alternatively, there is eliminatedthe amount of fuel which would escape through enlarged journals from thefuel chamber to the mixing chamber bypassing the metering device.

AIR VALVE 15 Inner Opening Annular body l6 has an inner wall 160 whichforms an inner central opening of air valve 15. Wall 1611 defines adownwardly and outwardly rounded surfacev An annular beveled surface .70of seat 17 smoothly mates with inner wall I60 when valve I5 is in thestatic rest position. As air valvc l5 moves upwardly, a straight-throughsmooth streamlined profile for airflow is provided through the inneropening of valve 15 and between seat 17 and valve 15, This streamlinedprofile is particularly important when valve 15 and seal 17 aresubstantially close to each other forming a sharp corner to air flow asfor example during idle and at low cruise speeds. A sharp corner ornonstreamline profile provides substantially more resistance to airflowthan a smooth streamline profile Thus the major portion of air flowingthrough the inner open ing flow with less resistance as compared with anonstreamline profile. it will be understood that the boundary layer ofair on and adjacent to the inside wall ofchamber 12 will be increased inthickness as compared with a nonstreamline profile, Thus the velocity ofthe air on or adjacent the inside wall is decreased.

Outer Wall Body 16 has an outer wall 16b adjacent to which inner wall[20 of chamber 12 is inclined in an upwardly and outwardly direction ina manner well known by those skilled in the art. As air valve 15 movesupwardly, the clearing for airflow between outer wall 16!) and innerwall 120 increases in area when the lower edge of wall 16!) passes thebeginning lZh oi inclined walls 120 Accordingly, with valve seat 17secured to stem 20 by lock screw 171* in the position illustrated. valve15 travels a substantial distance in response to a minimum de mand forair by the engine. At idle speed the engine demands a minimum amountofair and valve 15 is required to travel up wardly until the lower edgeof wall [6b passes the beginning 12b of the incline and until theminimum demand for air is satisfied. It will be understood that afterthe lower edge passes the incline beginning [2b, the air demand iscontrolled by the slope of the incline. This travel, of substantially ahigh order of magnitude, is transmitted to pin 34 thereby providing asub stantially large area clearing at idle. On the other hand, if valveseat 17 is secured to stem 20 at a position above that illustrated.valve 15 is required to travel upwardly a lower order of magnitude tomeet the engine minimum demand for air flow at idle. Accordingly, atidle speed the annular clearing between pin 34 and seat 37 is ofsubstantially less area than in the previous position of seat 17. Inthis manner, by varying the position of seat [7 the travel of valve 15may be adjusted to control the fuel air ratio at idle.

Travel Control Leaves The travel of air valve [5 may also be controlledby adjusting the position oftravel control plates or leaves 420-d, witheach of the leaves defining a segment ofa fiat washer, A slot is formedin each of the leaves 42a-d to receive a screw which is threadedlyengaged in an opening formed in the upper surface I61? of body 16. [nthis manner leaves 42a-d may be adjusted and then rigidly secured inposition to determine the effective inside diameter of the centralopening of air valve 15.

('iuides in order to guide the movement of air valve 15 there areprovided three downwardly extending projections l8a-c from annular body16. Projections l8a-c include downwardly extending keyways -4respectively for receiving respective guide pins 230-0 secured inchamber [2. in addition a longitudinal keyway ]'M is formed in thecylindrical inner wall of seat 17 for receiving a longitudinal key 178formed on the outer surface ofstem 20v lDLl': ADJUST The fuelair ratioat idle maybe finely adjusted by raising or lowering metering pin 34while valve 15 is in a static rest posi tion in the following manner.Metering pin 34 is fixedly secured to damper plate 36 which has a notchguide 360. Guide 36a is engaged by a vertical pin 45 secured to thevertically extending cylinder wall of a cylindrical damper housing 46surrounding plate 36. The lower end ofdamper housing 46 is closed andthere extends downwardly from the closed end a screwhead 46a which maybe turned from the outside ofcarhuretor 10 by inserting a screwdriver inhead 46a. Accordingly, by manually turning screwhead 460, housing 46 isrotated thereby rotating damper plate 36. metering pin 34 and rod 30Accordingly, as damper plate 36 is rotated the upper end oi rod .30 isscrewed into or out of threaded opening 281 of holder 28. in this mannermetering pin 34 may be raised or lowered with respect to waive scat 37while valve 15 is in the same static rest position VARIABLE DAMPINGDamping of air valve 15 is provided by fuel acting as a damping mediumon damper plate 36. As valve 15 and plate 36 go lower, fuel is forcedout of the volume of fuel between plate 36 and the lower closed end ofhousing 46. This fuel flows out through the relatively small clearing36a forming a fluid connection between the edge of plate 36 and theinner wall of housing 46 into the remaining fuel in chamber 22.Similarly, as valve 15 and plate 37 are raised, fuel flows from chamber22 through the fluid connection into the space between plate 36 and theclosed end of housing 46. it will be understood that this fluidconnection is of constant cross-sec tional area thereby producing aconstant damping factor In order to provide a variable damping factor,the fluid connection is eilectively varied in cross-sectional areathereby to vary the Hou ii fuel in the following inanrieiv As best shownin FIGS 4 and 5, a plurality ofequally spaced openings 47 are formedaround a circumference of housing 46 ad acent to the lower closed end. Adamper control cylinder 50 having a lower closed end 50a receives damperhousing 46 with sciewhead 46a extending through a central opening in end50a An annular shaped shoulder extends horizontally from the lowerclosed end 500 and has formed therein semicircular slots 50bc. ScrewsSla-b extend through respective slots SOb-c and engage threaded openingson the underside of a bottom base 56. Base 56 is fixedly secured to thebottom edge of housing I0 as for example by screws, It will beunderstood that base 56 may be an integral part of housing 10. Cylinder50 may be rotated about its axis by first loosening screws Sla-b andthen inserting a spanner wrench in the openings provided. Screws 5104:are then tightened.

The vertically extending cylindrical wall of cylinder 50 may be abouthalf the height of the wall of housing 46 with an O- ring seal 52 beingdisposed in sealing relation between the two walls. Below Oring seal 52and adjacent openings 57 there are provided in the wall of controlcylinder 50 two opposed elongated rectangular openings 54a-b. Base 56includes a vertically extending cylindrically shaped wall 57 whichextends above openings 54a-b. Opposing sections of wall 57 are beveledto form 57a-b. Lines drawn from the ends of sections 57a--b to thecenterline of base 56 form angles which may be approximately the same asangles formed by lines drawn from the ends of openings 54a-b to thecenter of cylinder 50. It will now be understood that an adjustablefluid connection may be ed from the fuel in housing 46 below plate 36through tings 47 leading to openings 54a and 54b, through beveled ions57a, 57b, to the fuel within chamber 22. The foregoidjustable fluidconnections are in parallel with each other with the constant fluidconnection through the side of 5 a 36 to provide a resultant adjustablefluid connection.

order to adjust the clamping, cylinder 50 may be rotated it its axis inthe manner previously described so that tings 54a-b are substantially inline with sections 57a-b actively. In this way there is provided aresultant fluid conion of maximum crosssectional area thereby to producemum damping. On the other hand, cylinder 50 may be Led so that openingsS4a-b are completely covered by vernonbeveled walls 57 so that theresultant fluid connection minimum cross-sectional area therebyproviding maxn damping. It will be understood that damper control der 50may be turned to positions between the foregoing :me minimum and maximumdamping positions to adjust lamping to an optimum level.

FLOAT CHAMBER 62-FUEL CHAMBER 22 .el is supplied to chamber 22 from afloat chamber 62 aining a float 65 by way of fluid connection or pipe60. 60 has an outlet in chamber 22 adjacent the bottom :of and an intakeopening 60a in chamber 62 which is .ed in the center of the projectedhorizontal area of iber 62. At best shown in FIG. 2 the horizontalprojected of chamber 62 defines a shaped section having curved s 62a-band straight edges 62c-d parallel to each other. ;e 60a to be in thecenter of the projected area is disposed :r to edge 620 than edge 62band equidistant between llel edges 62c-d.

locating intake 60a in the center of the area, it will be unood thatwhen the automobile carrying carburetor 10 the head of fuel at intake60a is maintained constant. For lple, the automobile tips to the rightthereby lowering the end and raising the left end of housing 10. Thus,in iber 62 the fuel is deeper in the right-hand end than in the landend, but the center of chamber 62 remains constant pth for a constanthead This constant head is maintained e automobile tips in anydirection. ln this manner there is :ved constant static fluid pressureat intake 600. e fuel in chamber 22 may not change in depth since the echamber is substantially filled with fuel as a result of the evel infloat chamber 62 being maintained above the top amber 22. Accordingly,with a constant static fluid presat intake 60a, the static fluidpressure is maintained conin chamber 22. Accordingly, the fuel feed tometering M is a function only of the suction produced in mixing lbCl 39and is not dependent on a varying fluid pressure. is manner moreaccurate control of the air-fuel mixture is ned, and therefore there isno cutoff or surge due to the 1g of the carburetor. With a separatefloat chamber 62 l fuel chamber 22 containing damper plate 36, there isald independent movement of float 65 and plate 36 ifically, when damperplate 36 rises, it is because the en requires more fuel from chamber 22and therefore float ay lower to allow more fuel to flow into chamber 62.If s two actions occur at the same time in the same lber, as in theprior art, the damper plate prevents the from swinging freely to feed infuel. Therefore, an uny fuel flow results which causes a hesitation ofthe engine irmance. This hesitation is caused since the flow of fuel thechamber is in a direction opposite that of damper 36 Accordingly, byseparating float chamber 62 from lbfil' 22, there is providedflexibility in allowing the float he plate to move without producinginterfering actions. lal 65 floats on the surface of the fuel in chamber62 and ecured thereto the lower end of a float arm 66 which as about apivot 68 and engages the left-hand end of a needle 70. When float 65 isat a lower position indicating .'"uel is required in chamber 62 theupper end of arm 66 moves to the left. thereby allowing fuel underessure in inlet 73 to push open valve needle 70 from valve seat 72 andto flow into chamber 62. When float 65 reaches its upper limiting level,the upper end of arm 66 pushes needle 70 to the right against valve seat72 thereby preventing fuel from flowing into chamber 62. The foregoingfloat and valving arrangement is adjusted so that the lower fuel levelis higher than the top of chamber 22 for the reason previouslydescribed. In addition inlet 60a is substantially below the lower fuellevel in chamber 62 to assure that no foaming fuel passes into chamber22.

It will be understood by those skilled in the art that suitable O-ringseals may be provided in sealing relation between cover 56 and chamber22 and between cylinder 50 and cover 56.

Float chamber 62 illustrated in FIGS. 1 and 2 may be replaced by afloatless constant level chamber as shown in FIG. 6. Carburetors withoutfloats are known in the art and have the advantage of avoiding the useof a float. When a float is damaged for example the carburetor floodsand fuel may escape from the carburetor onto the hot manifold causing afire.

However in prior floatless carburetors the overflow outlet has beenconnected to the side of a single chamber containing the float and thefuel chamber. Such a single chamber had the disadvantages describedabove. As illustrated in FlG. 6 a separate floatless chamber 80 isprovided for supplying fuel to chamber 22. As in the carburetor of FIGS.l5, tube 60 has an outlet in chamber 22 and an intake opening 60alocated in the center of the projected horizontal area of chamber 80. Aconstant flow of fuel enters by way of inlet 82 from a fuel pump (notshown). In this manner fuel fills chamber 80 until it reaches the levelof an overflow outlet opening 84 of a tube 85. The overflow fuel flowsinto opening 84 through overflow tube 85 back to the fuel tank (notshown). Tube 85 extends through a lower opening 88 of chamber 80 and issecured in place by a squeeze fitting 90 threadedly engaged in flange880. A gasket is disposed in sealing relation between fitting 90 andopening 88. To change the fuel level tube 85 may be moved upwardly ordownwardly by loosening fitting 90 and adjusting tube 85. Opening 84 isalways maintained above intake opening 60a.

Outlet opening 84 is located in the center of the projected horizontalarea of chamber 80. Thus, as the automobile tips the fuel becomes deeperat one end of chamber 80 with respect to the other end but the center ofthe area is maintained at a constant depth without the use of a float.Accordingly, the amount of fuel in chamber 80 is maintained constant. Aspreviously described with intake 60a in the center of the projectedhorizontal area, as the automobile tips a constant head is maintained onopening 60a. in this manner the static fluid pressure is maintainedconstant in chamber 22 and the fuel feed to metering pin 34 is afunction only of the suction produced in mixing chamber 39. Now that theprinciples of the invention have been explained, it will be understoodthat many more modifications may be made. For exam le, the four straightribs Isa-d forming a spider as shown in FIGS. l-4 may be twisted at aslight angle from the vertical center line of each rib as illustrated inFlG. 3A. Thus, ribs l5eh form a slight spiral and these ribs guide theairflow through the inner opening of air valve 15 to produce a smallswirl action in the fluid motion in chamber 12. This swirling action inconjunction with the thick boundary layer of air adjacent the inner wallcauses the heavier fuel particles in chamber 12 to drop downwardly to bebroken into small particles when they meet the fresh air entering fromintake ll. Thus there is provided an improved screen for fuel particles.

Iclaim:

l. A carburetor for an internal combustion engine comprismg a. a housinghaving an air intake opening and an output opening,

b. a chamber in said housing for mixing said air with fuel thereby toproduce a suspension of fuel particles in air,

c. fuel valve means communicating with fuel in a chamber for controllingthe flow of fuel to said mixing chamber,

fill

g ad ustable means for selectively varying the effective area ofsaidinner opening of said air valve means, said adjustable means comprisingsubstantially horizontal travel conllUl plates adjustably secured tosaid air valve means for movement radially to the axis of said air valvemeans for selectively varying said effective area of said inner open mg

1. A carburetor for an internal combustion engine comprising a. ahousing having an air intake opening and an output opening, b. a chamberin said housing for mixing said air with fuel thereby to produce asuspension of fuel particles in air, c. fuel valve means communicatingwith fuel in a chamber for controlling the flow of fuel to said mixingchamber, d. a float chamber for supplying fuel to said fuel chamber, e.a fluid coupling for flow of fuel having an inlet in said float chamberand an outlet in said fuel chamber, said inlet being disposed in saidfloat chamber to provide a constant static fluid pressure in said fuelchamber, f. air valve means moveable in accordance with the airflow fromthe said intake to said output opening, said air valve means having aninner opening for said air flow, and g. adjustable means for selectivelyvarying the effective area of said inner opening of said air valvemeans, said adjustable means comprising substantially horizontal travelcontrol plates adjustably secured to said air valve means for movementradially to the axis of said air valve means for selectively varyingsaid effective area of said inner opening.